Hunegnaw Chalachew B, Aure Temesgen W
Department of Civil Engineering, University of Gondar, P.O.Box 196, Gondar, Ethiopia.
Department of Civil Engineering, Addis Ababa Science and Technology University, P.O.Box 16417, Addis Ababa, Ethiopia.
Heliyon. 2021 Oct 19;7(10):e08193. doi: 10.1016/j.heliyon.2021.e08193. eCollection 2021 Oct.
The shear behavior of reinforced concrete (RC) beams has been a major research area for a long time. Since the shear response of RC beams is affected by different factors, many researchers have reported that the nature of shear behavior is complicated. One of these factors worth investigating is the inclination of shear reinforcements. This paper investigated the effect of the orientation of stirrups on the shear capacity of RC beams as the shear-span-to-depth ratio (a/d) varies. The contribution of concrete compressive strength was also studied. An experimental program investigating 21 RC beams has been conducted. The test results revealed that the shear capacity increases as the arrangement of stirrup changes from conventional vertical arrangement to inclined arrangement. However, the increment is high in beams with (a/d) ratio of 2.2 than beams with (a/d) ratio of 2.6, which are relatively slender. Shear capacity also increases as concrete compressive strength increase, which shows that concrete contribution to the shear capacity of beams should be taken in to account. In addition to the experimental test, the beams were analyzed numerically by using a general-purpose finite element package, Abaqus. The shear capacity of reinforced concrete beams obtained from the numerical analysis is in a good agreement with the experimental result. The results obtained by numerical analysis and experimental tests are compared to analytically calculated values by using shear provisions of ACI 318-14 and EN-2. Both ACI 318-14 and EN-2 are generally conservative in predicting the shear capacity of RC beams. However, the conservativeness of these codes reduced as a/d ratio of the beams increase.
长期以来，钢筋混凝土（RC）梁的抗剪性能一直是一个主要的研究领域。由于RC梁的抗剪响应受不同因素影响，许多研究人员报告称，抗剪性能的本质很复杂。其中一个值得研究的因素是抗剪钢筋的倾斜度。本文研究了随着剪跨比（a/d）的变化，箍筋方向对RC梁抗剪承载力的影响。同时还研究了混凝土抗压强度的作用。开展了一项针对21根RC梁的试验计划。试验结果表明，随着箍筋布置从传统的垂直布置变为倾斜布置，抗剪承载力会增加。然而，剪跨比为2.2的梁的增幅比相对细长的剪跨比为2.6的梁要高。抗剪承载力也随着混凝土抗压强度的增加而提高，这表明应考虑混凝土对梁抗剪承载力的作用。除了试验测试外，还使用通用有限元软件包Abaqus对梁进行了数值分析。数值分析得到的钢筋混凝土梁的抗剪承载力与试验结果吻合良好。将数值分析和试验测试得到的结果与使用ACI 318 - 14和EN - 2的抗剪规定计算得到的分析值进行了比较。ACI 318 - 14和EN - 2在预测RC梁的抗剪承载力时通常都较为保守。然而，随着梁的a/d比增加，这些规范的保守性会降低。
